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This weekend in the Bodgers Group our three Raspberry Pi Pioneers teams continued to work on their projects.

The Zombie Herders were working on a PIR (passive Infra-red) sensor which is the type of sensor commonly found in burglar alarms.

They used the GPIOZero library for Python and sample code which can be found here. However they didn’t have much success so we need to do more testing on our sensor and if necessary order a new one.

The zombie trolls worked on creating a 3-D model for their project using FreeCAD which they will print out when we return after the break.

I’m afraid I not allowed to discuss what it will be used for at this point :-).

Team Green Fingers worked on more scripts for their project including using their Arduino and a relay to switch a 12 volt automobile bulb on and off.

As with most projects like this we had a little trouble getting it going as we forgot to set the pin we used on the Arduino as an Output. Thanks to James and his Dad for bringing in the 12 volt powerpack.

We are off for the next two Saturdays and we’re back again on the 11th of November.

Hope you enjoyed this weeks session and remember we are off for the mid-term and so our next session is on the 11th of November.

To get ready for the spooky season we created a Halloween Scene, lots of scary sounds and switching of costumes to create the effect of movement.

I chose a Witch with a wolf howl but I saw lots of great ideas as I was going around the room. Some had Ghouls, others Vampires, its was all pretty scary.

We also learnt a nice trick for giving the allusion of movement. We had a bat change both its size and Costume and it worked very well to give the effect of the bat flying towards us with the moon behind it.

This week in the Hackers group, rather than demonstrating how to use SketchUo, we showed some models that Kevin/Michael had built (see above), and the challenge was to recreate them. Some people got so far as to be able to print their models.

We also started some planning on an overall theme – more on that next time.

Well! didn’t we have a very studious bunch of Ninjas last week, all very focused on our new game. Last Saturday we did a slightly different game to usual., There was no movement, no sensing when something happened. It was a Maths Game, a guessing game where the computer picks a random number and we had to guess the number.

We had to first make sure that a random number was picked using an Operator. Previously we have used a Variable to store a Score or Lives, but this time it was storing the random number and our guesses. Leaving them on screen as we were testing allowed us to understand more about the variable and what it does…it also made the testing a little easier.

Depending how any guesses we were given we repeated our code that number of times. As well as having to make decisions, i.e If_then, we also had to do a comparison before making the decision, to determine whether the guess was correct, too low or too high.

I hope you all enjoyed the difference this week and we are going try something else different next week. We (You) are going to create a Animated Halloween Scene. Get your Thinking Hats On!

Most of us had heard of a hard-disk before. This is a stack of metal disks inside your computer. Each metal disk has a special coating made of millions of tiny magnets (like you might find stuck to the fridge) that can be turned on and off.

We saw that able to turn something on and off, like a switch, was enough to count from zero to one, but the more switches we added, the higher we could count. Two switches can count from zero to three:

With enough of these tiny switches, we can store anything we need. Each of these tiny switches is also known as a ‘bit’ and a 1 terabyte hard disk has a billion of them!

We also saw that the files on your disk are arranged with folders (also known as directories). Folders can contain both files and more folders. This allow us to keep our hard disk organised; without them all our files would be in the same place which would be difficult once we had more than a few. The location of a file is called its “path”. Looking at the highlighted file on the desktop of my Mac we can see the full path would be:

/Users/kierancoughlan/Desktop/Ball and Bat Sounds.m4a

This means that, reading backwards, the file called ‘Bat and Ball Sounds.m4a’ is in a folder called ‘Desktop’ which is itself inside a folder called ‘kierancoughlan’ which is, at the highest level, inside a folder called ‘Users’.

Functions

A function is a collection of commands that do a job together. We’ve already encountered them, even if you hadn’t especially noticed:

All of the P5 commands we have used, such as createCanvas() and rect() are functions themselves

We could add all our code to start() and draw(), in fact, that’s what we’ve done before this week. That’s fine starting out, but it does mean, once there are a lot of commands in those functions, that our code is gets harder to read and understand. Breaking out a few commands into a new function and giving it a name that describes what it is doing, really helps.

Once we’ve written a function, it can be called as many times, and from as many places, we as need.

Functions can do one other thing too: they can give back a value to the place where they were called from. For this we use the special word return. For example, let’s see what a function to pick the largest of two numbers, we’ll call it Max(), might look like:

We give Max() the two numbers we are comparing. If the first one is bigger than the second, it gives back the first. Otherwise, if gives back the second. Note too that the names of the variables in Max() are different to those in start(), and that’s not a problem.

Random

Finally, we looked at the P5 function random(). We used it two different ways:

random(); // gives a number between 0...1
random(n); // gives a number between 0...n (where n is a number!)

In the first form, we used it to pick a random colour. In the second, we used it to pick a random position for our squares.

Files

As usual, all the code is on the creators github repository. Head there and download it!! The files for this week contain both the script we wrote (sketch.js) and a longer version that I wrote (sketch2.js). Feel free to take a look at both!

There was great excitement at this weeks session as the Pioneers teams opened their gifts from the Raspberry Pi Foundation. Each team member received a Raspberry Pi USB wristband, a Pioneers Lanyard, stickers and some sweets. Each team also got a copy of the Makers Guide to the Zombie Apocalypse and some zombie make-up.

We also got to see what was in our “Mystery Box” and I’m sure we are going to get great use out of it in future projects.

We then talked about the videos we’ll need a part of our entry and we had a look at a video from Pioneers on we need to put in our videos.

Then the teams spent some time planning out what they are going to do for their films.

At this week’s session, Kevin introduced everybody to SketchUp, a free 3D modelling program. Models built with SketchUp can be exported to a format suitable for input into Repetier Host, to prepare them for 3D printing.

Incidentally, other options for 3D modelling include Blender (which some may have used previously for modelling) and TinkerCAD (which is web-based so does not require installation).

Here are some notes on getting started with SketchUp – they are taken from an NUI Galway summer camp I was involved in organising a couple of years ago: sketchupnotes

By the way, the picture above is a SketchUp model I built previously of a room.

Important: to export SketchUp models to Repetier, you first need to install the SketchUp STL Extension. Instructions:

n the SketchUp main menu, select Window – Extension Warehouse.

Search for SketchUp STL (see below), then go through the steps of downloading and installing.

Note that you may need to create a Trimble account (Trimble is the company that develops SketchUp).

You may see a warning that it is not marked as compatible with your version of SketchUp, but just press OK.

After installing the SketchUp STL extension, you will have a new menu item: File – Export STL.

This week the creator crew learned some of the most important things for coding and we managed to build quite a useful app while we were at it! For those that missed this week, we handed out two sheets which … Continue reading →

Great week again with huge crowds but thanks to our new room layout and a couple of Health and Safety issues sorted, I think it was a more comfortable and safe environment for everyone. Thank you to Niamh, Sarah, Roisin , Alan and Pete you came early and helped sort out the new layout.

This week, I helped Bo Peep found her sheep! Some of you did the same and some used ideas like Minecraft Steve finding Iron Ore and Diamonds, Knights finding dragons or a Princess finding flowers.

Before we even started our game this week we talked a little bit about File Management and about the importance of keeping your files somewhere you can access them quickly and giving them a meaningful name.

So to this end, we all created a folder where we will be keeping our files in the future and within that we had a sub folder for this weeks files.

We started our game by drawing our background on our stage:

Rather than use the sprites from the Scratch Library, we searched the internet using a image search for our Sprites.

This week, we decided to move our main sprite using the arrow keys. For this we had to learn a small bit about the X and Y axis and I gave you a little tip on how to remember which is which!

Hope you all enjoyed this week, next week we have a very small bit to finish off for this game and then we will start a new game!